Hard? Crikey, those are the EASIEST door panels I've every dealt with!
Just pry off the trim, remove the top armrest screw, unclip the latch
"bucket", remove the seat switch bits, and unscrew the lock button and
lift off. Takes me all of three minutes (needless to say, I've done a
few). Lots of broken hooks in the bottom of the doors, no one ever
looks in the manual to check, I suppose.
both of my 124 chassis cars have had door panels pried off -- had to
replace the right rear this year because the armrest pulled away.
Peter